"On November 18, 1867 five o'clock in the afternoon, the water in the
harbor dropped five feet. The reef in front of the lagoon was exposed.
Then the water in the harbor rose quickly to four feet over normal height
and rushed up to the head of the Carenage. This happened three or four
times. Much damage was done to boats and buildings but fortunately no lives
were lost."

As if having a hurricane season isn't enough excitement! The Caribbean
also has volcanoes, and now the prospect of tsunamis has again reared its
head.
Tsunamis are waves formed when huge masses of water are displaced by
undersea volcanic eruptions or earthquakes. A single wave is normally less
than a few meters high in the open ocean, but can extend more than 750
kilometers (465 miles) in length in the open ocean. This creates a sea-surface
slope so gentle that the wave usually passes unnoticed in deep water. But
as the waves transport seismic energy from their source, they travel up
to 800 kilometers (500 miles) per hour and may build up to devastating
heights when they approach land.

The recent major eruptions at Montserrat have made people more aware
than ever that this is a volcanic region. The islands of the Eastern Caribbean
lie along the Lesser Antilles volcanic arc. Volcanoes occur where the various
moving plates which make up the Earth's surface meet. The volcanoes in
the Lesser Antilles arc are located along the edge where the South American
Plate is pushing itself under the Caribbean Plate.

Now cruising in the Caribbean, Ian Deas of the yacht Manx Cat relates:
"We experienced a tsunami in Yugoslavia in 1978 resulting from an earthquake
in Greece. We were in a lagoon with a narrow entrance, rafted alongside
a friendly larger yacht and having a convivial drink when we sank! The
quay rose by one and a half meters or so, then dropped by the same. We
were only on our second gin and tonic and realized that it was no hallucination
as we sank and rose a couple more times.

"Two days later we sailed into Korcula to find it a disaster area, with
big fishing boats high and dry on the quay, and shops with their fronts
smashed in and high water marks up to their first floors. The sea had run
out of the harbour, grounding all the boats. The ensuing tidal wave had
snapped mooring lines, and even boats that had held their moorings were
wrecked. Korcula harbour is at the head of an estuary; a wave which was
small at the entrance was magnified, so that when it arrived at the quay
it must have reached ten meters. We were lucky that our lagoon had a small
entrance."

The Kick 'em Jenny volcano is active, there is no doubt about that.
According to the Global Volcanism Program of Smithsonian Institution, it
has erupted ten times since 1939, with the most recent eruption occurring
in 1990.
"Marine and aviation warnings have been out for years, but yachts,
schooners and ferries continue to go right over it," says Tony Buxo, a
member of Grenada's National Emergency Advisory Council.

Ian Deas recalls: "A few years ago the Grenada Coast Guard gave out
a security warning to give this area a wide berth of at least six miles.
We came past the island two days later and gave it an offing of over a
mile compared to our usual half mile, with nothing to be seen, felt or
smelt. We were rather disappointed not to be given a whiff of sulphur.
Perhaps we were foolhardy."

Perhaps. Although most eruptions of this volcano have been identified
by the detection of strong underwater acoustic signals at regional seismograph
stations, the 1939 eruption sent a black cloud up to 885 feet (270 meters)
above sea level, and during the 1974 eruption the sea above the volcano
boiled turbulently and spouted steam; shoals of fish were found "belly-up"
west of the site.

Kick 'em Jenny volcano is located at approximately 12·18'N, 61·38'W,
just west of The Sisters rocks and Ile de Ronde, and about 6 miles (9 kilometers)
north of Grenada. Nearby Ile de Caille is made up of two youthful craters
and lava flows. Kick 'em Jenny is the southernmost active volcano in the
Lesser Antilles volcanic arc and, although at a number of scuba diving
sites such as "Champagne" in Dominica and one area of "Mayreau Gardens"
near the Tobago Cays, bubbles trickle up from the bottom signalling local
volcanic activity, Kick 'em Jenny is the only active submarine volcano
in the arc.

Kick 'em Jenny has a basal diameter of about 3 miles (5 kilometers)
and rises about 4,300 feet (1,300 meters) above the sea floor. Its summit
grew from about 235 meters (770 feet) below the sea surface in 1962 to
about 150 meters (492 feet) in 1982.

Editor Jack Dausend wrote in The Boca, July '99 "researchers have estimated
that at the current rate of ascent the volcano could emerge above sea level
early in the 21st century. In 1988 a researcher dove on Kick 'em Jenny,
documenting its size and contour on video, and at that time verified its
depth as 150 meters below sea level. It last erupted in 1990, and it is
thought that its top blew off with that eruption." (because the most recent
measurement placed the summit 27 meters [88 feet] lower, at a depth of
177 meters [581 feet].)

The following table, provided by the Seismic Research Unit (SRU), shows
depth measured by various vessels since 1962:

The SRU plans to make another survey soon. The distance from the
volcano's summit to the sea surface is critically important, and the consistent
diminishing of this distance (except for the most recent recording) is
one of the reasons Kick 'em Jenny has recently received so much attention.

What's happening, explains Dr. John Shepherd who is Head of Seismic
Research at the SRU and who first surveyed Kick 'em Jenny in 1974, is that
the periodic eruptions since the first was recorded on 24 July, 1939, have
resulted in the summit of the volcano climbing closer and closer to sea
level. The weight of the sea, when the summit remains deep, dampens the
energy of the explosions, although some have already broken the surface.
But as the summit gets nearer to the surface, the explosions will become
more violent, with the resultant increased possibility of a tsunami.

News of the volcano's growth toward the surface has spawned some hysterical
reports in the media. This past February, Grenada resident Dave Hadley
was told by his dentist in Canada that Grenada was about to be swamped
by a 100-foot wall of water. "We had been delayed in our return to Grenada,"
says Dave, "and he felt that I should be glad not to be in the danger zone."

Apparently a Montreal newspaper had picked up a wire-service report
indicating that Kick 'em Jenny was being monitored for future eruptions
and a possible tsunami and the newspaper added its own prediction that
this would occur within 48 hours of the story's publication!

Other alarms have been generated by sailors unfamiliar with the rough
seas often encountered in the vicinity of Kick 'em Jenny. "The number of
rumors from passing mariners has even managed to trickle as far as Washington,
DC," says Rick Wunderman of the Global Volcanism Program of the Smithsonian
Institution. "And we have received calls from Venezuela. "
But Compass correspondent Norman Faria reports that, speaking at a
public lecture sponsored by the Central Emergency Relief organisation (CERO)
in Barbados in early June, Dr. Shepherd said there's no need to worry at
this time. "It's not about to blow up." Dr. Shepherd emphasises that no
eruption is imminent and there are no signs of unusual activity at Kick
'em Jenny although, because future eruptions are expected, the SRU is strengthening
its monitoring of any renewal of activity.

Monitoring of volcanic activity throughout the English-speaking Lesser
Antilles has been conducted for decades by the SRU. Dr. Shepherd, who joined
the SRU in 1964, says, "My first field project on a real volcano was the
Kick 'em Jenny eruption in 1965. We'd suspected there was a volcano in
that area so we went to Sauteurs and the people there knew all about it.
In fact, Father Divas, a Jesuit priest in Grenada, had written a detailed
account of the 1939 explosion." Dr. Shepherd says Kick 'em Jenny has been
his "pet project" since then.

He says that a particular concern, as the volcano's summit approaches
the sea surface and thus the weight of overlying water decreases, is that
samples of rocks collected from eruptions over the past 20 years show that
Kick 'em Jenny's magma contains a high proportion of dissolved water (water
in molecular form), which is an indicator of high explosivity. "The water
molecules are like the gas molecules in a bottle of champagne," he explains.
They'll stay dissolved until the pressure is released, then POP! Dr. Shepherd
notes that Kick 'em Jenny is one of the very few submarine volcanoes in
the world having this particular combination of molten rock with a high
water content, and near-surface depth, making it especially explosive.

According to a May 1999 article in Scientific American magazine, 82
tsunamis have reported worldwide since 1990. This report rate higher than
the historical average of 57 a decade is due to improved global communications.
The majority of tsunamis affect the Pacific Ocean, and most of those are
the products of undersea earthquakes around the Pacific Rim. Tsunamis in
the Caribbean have been relatively rare.

Nevertheless, a recent Caribbean Development Bank newsletter warns,
"With regard to Kick 'em Jenny, studies have indicated that in the event
of a major eruption, tsunamis may be generated which could reach as far
as Puerto Rico to the north and Trinidad and Venezuela to the south." Dr.
Shepherd says that the islands most directly affected in the case of a
tsunami would be Grenada, the Grenadines, St. Vincent, Tobago and Barbados,
although some effects would be felt further north and as far south as the
north coast of Venezuela. He notes that tsunamis do not radiate evenly
from their source, like rings from a pebble dropped in a pond, but are
affected by islands and the shape of the ocean floor. "A tsunami from Kick
'em Jenny would be funneled by the Aves Ridge toward St. Maarten, Anguilla
and the Virgin Islands," he says.

Recent alarmist accounts in the media quoted out of context from a hypothetical
"worst case scenario" which had been developed for a published doctoral
thesis by one of Dr. Shepherd's students. This worst case was based on
a theoretical assumption of an eruption at Kick 'em Jenny being of the
same intensity as the 1883 eruption of Krakatoa in Indonesia, the strongest
volcanic explosion in human history. Is such a scenario likely? Not very.
The erupted volume (one measure of a volcano's intensity) of Krakatoa was
about 9 square kilometers of dense rock; the erupted volume of Kick 'em
Jenny's historic eruptions are estimated not to have exceeded one-tenth
of a square kilometer of rock, giving Krakatoa's famous eruption 90 times
the erupted volume of a typical Kick 'em Jenny eruption.

"Kick 'em Jenny's eruptions are frequent, but small," say Shepherd.
"Our hypothetical worst case scenario was for forty-meter waves in the
Grenadines, but the realistic worst case scenario is for fifteen-meter
waves and in the most likely scenario, waves would probably not be much
worse than the swell from a near-miss hurricane." The SRU's "high probability"
predictions (based on Kick 'em Jenny's 1939 eruption, which caused a 1-
to 2-meter tsunami in Barbados) forecast a 3 meter wave at Grenada's north
coast, diminishing to under one meter by the time it reaches Port of Spain,
Trinidad.

"Nevertheless, we have to be prepared," warns Shepherd. Eruptions of
Kick 'em Jenny can be predicted, says the SRU, since the volcano needs
time to build up to full eruption. Therefore volcano-generated tsunamis
can be predicted by monitoring the volcano, and a progressive series of
warnings could be issued as the eruption approaches.

The Caribbean Development Bank (CDB) has recently provided a grant of
up to US$170,600 to the SRU for the establishment of means for continuous
monitoring of the volcano, and USAID/OFD have provided an additional US$60,000
toward a public information campaign. For this project, the University
of the West Indies, through the SRU, in collaboration with the Caribbean
Disaster Emergency Response Agency (CDERA), will engage professional, technical,
and support staff and services. The CDB financing will meet consultants'
fees, and the costs of equipment, sensitization workshops and involvement
of regional disaster preparedness agencies. Public lectures have already
been given in Barbados, St. Vincent, Grenada and Trinidad.

Inundation models showing areas likely to be flooded will be generated
by computer, and recommendations on evacuation procedures will be made.
Some volcano monitoring devices are already in place at Mount St Catherine,
and additional equipment will be installed at Ile de Ronde, Sauteurs (on
Grenada) and Carriacou.

The schematic diagram above illustrates the technical details of the
proposed tsunami warning center. All data are transmitted to a center where
they are recorded and monitored in real-time or near real-time. Data is
fed to a computer which logs and displays the incoming information. At
the local warning center a seismometer (an instrument which measures the
direction and force of eruptions) will provide accurate recordings of volcanic
activity. Another instrument will be used to provide continuous visual
recordings of information from the Ronde Island station. The third workstation
is to retrieve and process data from the acquisition computers. Each acquisition
machine will be equipped with "event triggers" which will be tuned to recognize
events which could generate a tsunami.

Still, as the article "Tsunami!" in May's Scientific American admonished:
"Predicting where a tsunami may strike helps to save lives and property
only if coastal inhabitants recognize the threat and respond appropriately.
technology alone cannot save lives. Coastal inhabitants must be [ready
to] seek higher ground immediately." As Tony Buxo of Grenada's National
Emergency Advisory Council recommends, "If you feel a big rumble, don't
bother to pick anything up; just head for higher ground. If you're on a
boat, head offshore."

"Part of the education programme about the potential dangers from Kick
'em Jenny is to warn residents not to go into the dry seabed to collect
stranded fish shortly before the tsunami strikes. That happened in the
Pacific, and the people weren't fast enough to get back to shore when the
tsunami did arrive," says Dr. Shepherd.

He also warns, "Marine advisories on Kick 'em Jenny are genuine. Imagine
a meter-diameter rock fired directly upward at a hundred miles per hour."
Ian, who experienced that tsunami in Yugoslavia, suggests: "Look around
your present environment. Would it be safe?" Keep in mind that a tsunami
wave may carry huge quantities of sand, rocks, vessels and debris, as well
as water.

And after the eruption which may occur when Kick 'em Jenny reaches the
point estimated by Dr. Shepherd to be about 150 meters or less from the
surface of a potentially tsunami-causing explosion?

"Once Kick 'em Jenny gets above the surface, it will form an island
which will, most likely, look a lot like Ile de Caille. It could grow to
the surface soon" Dr. Shepherd says, "or it could just blow the top off
itself and be quiet again for a century."

Information from the Seismic Research Unit of the University of the
West Indies, the Global Volcanism Program of the Smithsonian Institution,
Volcano World website (http://volcano.und.nodak.edu/), correspondents Norman
Faria, Dave Hadley and Ian Deas, the CDB News (Caribbean Development Bank
newsletter), Scientific American magazine (May 1999) and the Journal of
Volcanology and Geothermal Research (1995) was used in this report.